Manual shift control device of a transmission control system for an automotive automatic transmission

Abstract

A manual shift control device of a transmission control system for an automotive automatic transmission. A solenoid feed valve feeds line pressure passing through a pressure regulator valve to first, second and third solenoid valves. A torque control regulator valve changes drive pressure into torque pressure. A control switch valve alternatively feeds torque pressure to first and second torque pressure passages. An N-D control valve sequentially feeds torque pressure and drive pressure to a second friction member, which is applied at an initial shift operation together with a first friction member, to thereby alleviate shift shock from neutral range "N" to drive range "D". A first-to-second speed shift valve feeds part of the torque pressure and part of the drive pressure to a third friction member during a shift operation from the first speed to the second speed. A second-to-third speed shift valve feeds part of the torque pressure as well as part of the hydraulic pressure to a fourth friction member during a shift operation from the second speed to the third speed. A third-to-fourth speed shift valve feeds part of the torque pressure as well as part of the hydraulic pressure fed to the fourth friction member and, at the same time, interrupts the hydraulic pressure feeding to the first friction member during a shift operation from the third speed to the fourth speed. The third-to-fourth speed shift valve feeds drive pressure to the seventh friction member when manual shifting from the fourth speed to the second speed of a second "2" range. An N-R control valve feeds hydraulic pressure to a sixth friction member during reverse "R" range. A shock alleviator absorbs shift shock by the hydraulic pressure.

What is claimed is: 
     
       1. A manual shift control device of a transmission control system for an automotive automatic transmission, comprising: a hydraulic pump for generating hydraulic pressure, the hydraulic pump being operated by the driving force of an engine;   a pressure regulator valve for regulating hydraulic pressure generated from the hydraulic pump in response to the vehicle's driving conditions;   a solenoid feed valve for feeding line pressure passing through the pressure regulator valve to first, second and third solenoid valves via line pressure passages;   a manual valve for feeding hydraulic pressure to a drive pressure passage in a drive "D" range and to a reverse pressure passage in a reverse "R" range while varying its ports in accordance with the position of a shift selector lever;   a torque control regulator valve for changing drive pressure fed from the manual valve into torque pressure in accordance with the duty-control of a third solenoid valve;   a control switch valve for alternately feeding torque pressure fed from the torque control regulator valve to first and second torque pressure passages in accordance with the ON/OFF operation of a fourth solenoid valve;   an N-D control valve for sequentially feeding torque pressure and drive pressure to a second friction member, which is applied at an initial shift operation together with a first friction member, to thereby alleviate shift shock occurring in a shift operation from a neutral range "N" to the drive range "D";   a first-to-second speed shift valve for feeding part of the torque pressure fed from the first and second torque pressure passages as well as part of the drive pressure fed from the manual valve to a third friction member through a second clutch valve while varying its ports in accordance with the ON/OFF operation of a fifth solenoid valve during a shift operation from the first speed to the second speed of the drive "D" range;   a second-to-third speed shift valve for feeding part of the torque pressure fed from the first-to-second speed shift valve as well as part of the hydraulic pressure fed to the third friction member to a fourth friction member through a third clutch valve while varying its ports in accordance with the ON/OFF operation of a sixth solenoid valve during a shift operation from the second speed to the third speed of the drive "D" range;   a third-to-fourth speed shift valve for feeding part of the torque pressure fed from the second-to-third speed shift valve as well as part of the hydraulic pressure fed to the fourth friction member through a fourth clutch valve and, at the same time, interrupting the hydraulic pressure feeding to the first friction member while varying its ports with the operation of a seventh solenoid valve during a shift operation from the third speed to the fourth speed of the drive "D" range, the third-to-fourth speed shift valve feeding drive pressure fed from the manual valve to the seventh friction member through the third and second clutch valves during a manual shift operation from the fourth speed of the drive "D" range to the second speed of a second "2" range;   an N-R control valve for feeding hydraulic pressure fed from the manual valve via the reverse pressure passage to a sixth friction member while varying its ports in accordance with the control of the third solenoid valve in the reverse "R" range; and   a shock alleviating means for absorbing shift shock by hydraulic pressure;   wherein the shock alleviating means comprises a first accumulator being controlled when the shift mode changes from the fourth speed of the drive "D" range to the second speed of the second "2" range as well as to the second speed of the drive "D" range, the fifth friction member is controlled, and hydraulic pressure is applied to the sixth friction member by the mechanical control.   
     
     
       2. The manual shift control device of claim 1, wherein the shock alleviating means comprises a second accumulator A2 being disposed on the passage for feeding hydraulic pressure from the N-D control valve to the second friction member to absorb shift shock generated by torque pressure. 
     
     
       3. The manual shift control device of claim 1, wherein the shock alleviating means comprises a fourth accumulator A4 being disposed on the passage for feeding hydraulic pressure from the second clutch valve to the seventh friction member to alleviate shift shock generated by drive pressure. 
     
     
       4. The manual shift control device further comprising a power train, wherein the power train comprises: an engine being a power source;   a torque converter connected to a crankshaft of the engine;   a first shift part comprising a compound planetary unit, which is composed of two simple planetary gear units, the compound planetary unit having a first sun gear being formed in a body with a second shaft to thereby selectively work as an input element, the second shaft being connected to a first shaft by inserting the second friction member therebetween, a second pinion gear being connected to a first ring gear through a second power transmission member to be controlled by a first one way clutch and the sixth friction member therebetween and thereby work as a reacting element, a first pinion gear being connected to a second ring gear through a third power transmission member to be an output element, and a second sun gear being formed in a body with a second shaft to selectively work as an input element, the second shaft being connected to the first shaft by inserting a first power transmission member and the fourth friction member therebetween, the second sun gear being controlled by a second one way clutch and the third and seventh friction members to thereby be a reacting element;   a second shift part comprising a simple planetary gear unit having a third ring gear meshing with a first output gear of the first shift part to be an input element, a third pinion gear meshing with the third ring gear to be an output element, a third sun gear being controlled by a third one way clutch and the first friction member to thereby be a reacting element.